Embodiments of the present invention relate to and claim priority to Japanese Patent Application No. 2000-398367, filed on Dec. 27, 2000.
1. Field of the Invention
The present invention relates to an electronic pad for use as an electronic percussion instrument, and in certain embodiments, for use as an electronic hi-hat cymbal.
2. Description of the Related Art
In recent years, electronic musical instruments have secured a position not simply as an alternative to acoustic musical instruments but as musical instruments capable of generating tones of various timbers with various effects.
One such electronic musical instrument is an electronic percussion instrument that imitates an acoustic percussion instrument. One technique relating to electronic percussion instruments, and specifically, a technique for allowing an electronic percussion instrument to generate tones similar to those of an acoustic percussion instrument, is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 5-143071, which is incorporated herein by reference.
According to the electronic percussion instrument disclosed in JP-A No. 5-143071, a phenomenon occurs such that the initial amplitudes of vibrations caused by percussive strikes against the instrument may vary depending on where the instrument was struck. Moreover, the initial amplitudes of such vibrations may vary even if different parts of the instrument are struck with an equal striking force.
Next, experimental data on the above described phenomenon will be described.
FIG. 1 shows an electronic pad 7 similar to an embodiment of the electronic pad disclosed in JP-A No. 5-143071. The electronic pad 7 has a frame 2 that transmits a vibration of a strike, a striking sensor 1 that detects the vibration of a strike wherein the striking sensor 1 is arranged on the central portion of the lower surface of the frame 2, and a cover 3 which is in contact with the frame 2 and that covers the upper surface of the frame 2.
FIG. 2 is a top view of the electronic pad 7 shown in FIG. 1. For illustrative purposes, the striking sensor 1, which would not normally be seen in a top view, is shown. The striking surface of this electronic pad 7 is the area inside a circle having the radius A (A being measured from the center of the electronic pad 7). As shown in FIG. 2 and for purposes of discussion herein, a point a distance xe2x80x98axe2x80x99 away from the center of the electronic pad 7 will be referred to as a point xe2x80x9cinside,xe2x80x9d a point away therefrom by distance xe2x80x98bxe2x80x99 will be a point xe2x80x9cmiddle,xe2x80x9d and a point away therefrom by distance xe2x80x98cxe2x80x99 will be a point xe2x80x9coutside.xe2x80x9d The ratios of the distances xe2x80x98axe2x80x99, xe2x80x98bxe2x80x99, and xe2x80x98cxe2x80x99 to the radius A are 10%, 50%, and 90%, respectively.
FIG. 3 is a waveform view showing waveforms of vibrations detected by the striking sensor 1 (shown in FIG. 2). The three waveforms correspond to when points xe2x80x9cinsidexe2x80x9d, xe2x80x9cmiddle,xe2x80x9d and xe2x80x9coutsidexe2x80x9d on an electronic pad are struck by a percussion member, such as a stick, with an equal striking force. The solid line indicates a waveform detected when the point xe2x80x9cinsidexe2x80x9d is struck, the dashed line indicates the waveform when the point xe2x80x9cmiddlexe2x80x9d is struck, and the dotted line indicates the waveform when the point xe2x80x9coutsidexe2x80x9d is struck. A comparison of the amplitudes of the waveforms shows that the initial amplitude of the waveform corresponding to when the point xe2x80x9cinsidexe2x80x9d is struck is the highest. The initial amplitude of the waveform corresponding to when the point xe2x80x9coutsidexe2x80x9d is struck is the lowest. The initial amplitude of the waveform corresponding to when the point xe2x80x9cmiddlexe2x80x9d is struck is in between the others.
In the case of an acoustic percussion instrument, the volume thereof does not depend on the striking position on the striking surface. Instead, a sound is generated with a volume closely related to the strength of the strike (the xe2x80x9cstriking strengthxe2x80x9d). A conventional electronic percussion instrument, by contrast, may not generate a sound with a volume related to the striking strength because of the above-described phenomenon. The initial amplitudes of the waveform vibrations may vary even though different positions may be struck with the same striking strength.
Accordingly, conventional electronic percussion instruments may need to detect a striking position as well as a striking strength. By accounting for a striking strength as well as a striking position, an electronic percussion instrument may correct the volume so that a sound may be generated with a volume according to the striking strength irrespective of the striking position.
Therefore, conventional electronic percussion instruments, to accurately correct the volume according to the striking strength, may also need to detect the striking position. Further, to generate a sound without creating a delay from the time of the strike, any volume corrections must be done very quickly. Accordingly, it is a disadvantage of conventional electronic pads that they may have to promptly detect striking position and correct the detected striking strength.
In view of the above, it is an object of embodiments of the present invention to provide an electronic pad that may detect a striking force without having to detect or account for the striking position.
To obtain the above-described object, an electronic pad according to embodiments of the present invention may comprise:
a disk-shaped or bowl-shaped frame curved upward or downward;
a striking sensor in contact with the frame; and
a cover in contact with, and covering, an upper surface of the frame, and formed out of a softer material than the material of the frame.
The frame 2 of a conventional electronic pad may be constituted out of a flat plate as shown in FIG. 1. The electronic pad according to the present invention, by contrast, may have a disk-shaped or bowl-shaped frame curved upward or downward. Due to the shape of the frame, a strike against an outer peripheral portion of the electronic pad may be transmitted to the striking sensor without being greatly attenuated as compared to a strike against a position inside of the outer peripheral portion.
In some embodiments of the present invention, the frame of the electronic pad may be convex and curved upward. Also, the striking sensor may be situated such that it is in contact with a central portion of a lower surface of the frame.
In addition, in some embodiments of the present invention, the electronic pad may further comprise a chassis having a protrusion on one surface that forms a circle or a ring. In such embodiments, the cover may extend around to a lower surface of the outer edge portions of the frame, thereby holding the frame. In these embodiments, the chassis supports the outer peripheral edge portions of the frame, with a portion of the cover being interposed between the chassis and the frame. Further, in some embodiments of the invention, the outer edge of the frame may not be extended beyond the protrusion of the chassis.
Embodiments of the invention may also employ a sheet sensor for detecting an applied pressure on edge portions of the cover. The sheet sensor may be disposed at a position on an upper surface of the chassis outside of the chassis protrusion. In such embodiments, the cover may have a cover protrusion on its bottom surface that may press the sheet sensor in response to a strike against the upper surface of the cover. In this embodiment, the cover may also have a hollow portion outside of the protrusion.
In electronic pads according to embodiments of the present invention, a portion of the cover near the striking sensor may be formed thicker than other portions of the cover. If the portion of the cover under which the striking sensor is provided is formed to be thicker than the other portions of the cover, then a strike against the cover above the striking sensor may be attenuated so that such a strike is not detected more excessively than strikes against other portions of the cover.
In electronic pads according to further embodiments of the present invention, a surface treatment may be applied to the cover, such as a rubber primer. The cover may also have concentric concave and convex configurations on a surface of the cover.